Like Jiro with sushi, Sunny Yim dreams of ramen. Obsession might be too mild a term: Yim pores over the weather report, thinking how the next day's temperature and humidity will affect the amount of water he'll add to his noodle dough.

You quickly realize Yim, chef/owner of the new Wicker Park restaurant Oiistar, can riff ramen for hours and not run out of things to say. Here's a man who appreciates ramen on such a visceral, depths-of-his-soul level he's devoted his last five years to learning all its peculiarities. Now, he's opened perhaps the only restaurant in town that makes its ramen noodles in-house.

The centerpiece of his ramen enterprise is a $65,000 noodle-making machine by the Yamato corporation, imported from Japan. This isn't some hand-crank contraption; it's wheeled in and requires an electric outlet, with wooden dowels and metallic panels — at once old-school and futuristic — plus warning stickers throughout depicting chopped-off fingers.

Ramen, Yim tells me, is impossible to make by hand. Kneading doesn't provide sufficient downward pressure to attain the ideal density in the dough. Try, and you end up with porous noodles that absorb broth, expand in the bowl and turn soggy.

So what exactly does a machine that costs as much as a Tesla Model S electric car do? It compresses the dough — consisting of high-protein flour, egg white, filtered water and alkaline — into a pliable, taut sheet that coils itself around the dowel like a roll of paper towels. Then, it's extruded through the cutter. If you look at the individual strands, the width of capellini, you notice each noodle has four corners. The theory: A noodle with more surface area and edge clings to the broth better, adding more flavor with every slurp than a cylindrical noodle would. I think the taste difference is negligible for 99 percent of people, but an evangelist like Yim who fights for every competitive edge is admirable.

Discussing the broth requires biographical context. Yim, a Korean native, has a French and Italian culinary background and spent years at the Swissotel on Wacker Drive. Like many ramen faithful, his awakening came during a trip to Tokyo. He saw the exploding success of New York City purveyors Momofuku Noodle Bar and Ippudo, coupled with Chicago's ramen void, and pounced on the opportunity. A return visit to Japan and 50 ramen shops later, Yim decided to dive into the ramen world headfirst.

He attended a two-week ramen crash course in Japan. After taste testing nearly two dozen different broths extracted from every conceivable animal bone, Yim declared the broth from pork back rib bones to be the most delicious. At Oiistar, the base broth requires just three ingredients: pork back bones, filtered water and 18 hours of cooking. The resulting broth is the point-of-entry in Yim's house special, Oiimen, closest to the Hakata-style of ramen, distinctive in two respects: 1) thinner, more toothsome noodles, and 2) that aforementioned rich, milk-colored pork broth, known as tonkotsu.

At its most transcendent, tonkotsu broth will curl the toes and send a warm blush from torso to extremities. Its closest approximate is perhaps a white truffle bisque, bearing that same buttery, lip-licking mouthfeel. Except tonkotsu broth resonates deeper, a flavor so dense that it tastes one click left of too salty — without any salt added.

What makes Oiistar worth seeking out is that as an entry-level tonkotsu in Chicago, the broth isn't so over-the-top rich that it makes diners feel they just consumed a prime rib. A number of ramen houses outside Chicago fortify their tonkotsu broth with extra pork fat — you can see a quarter-inch layer of oil floating on the soup's surface.

Some folks go nuts for that, the same people who eat habanero peppers whole for the thrill. But finishing off a bowl at Oiistar doesn't equate to a pit-of-the-stomach heaviness. Yim tempers the richness by skimming off excess fat throughout the stock-making process. (There's also a vegan broth on the menu.)

The end product from five years of development is its house special, Oiimen ($14) — crunchy strands of tree ear mushroom, scallion tangles, succulent coaster-size discs of pork loin, a hard-boiled egg cooked to a barely congealed yolk, each partitioned to its own section of the bowl. In lieu of additional pork fat are droplets of garlic and chili oil, and somewhere lurking in the broth are those $65,000-machine-cut noodles. Like discerning the difference between dried and fresh pasta, the taste and texture are noticeable — that fresh-flour linger, a softer through-bite while retaining some semblance of al dente.

Yim is something of a trailblazer, investing the labor so as to approach this tonkotsu ideal and make it available to the masses. Oiistar's version is a worthy introduction. Outside of trekking to Santouka in Arlington Heights (better broth, but the noodles are shipped in), you won't find a finer version within Chicago city limits.